Dr. James Andrews was on Sirius/XM radio’s “Power Alley” with Mike Ferrin and Jim Duquette yesterday, talking about Tommy John surgery. He was asked why there seem to be so many guys needing TJ surgery these days.

His answer: it’s not an anomaly, it’s a trend. And an alarming one, he says, in that so many more of the surgeries he’s performing are for high school pitchers as opposed to professionals with a few years under their belt. Kids are bigger and stronger these days, and their ability to throw harder is outpacing the development of their ulnar collateral ligaments.

But the biggest risk factor he and his researchers are seeing: year-round baseball. The fact that not only do pitchers throw year-round, but that they are pitching in competition year-round, and don’t have time to recover. Also: young players are playing in more than one league, where pitch count and innings rules aren’t coordinated. Another factor: the radar gun. Young pitchers who throw over 85 or so are at risk, and all of them who are on a major league track are throwing that fast or faster, and are going up in effort when scouts with guns are around.

Ultimately, you can’t prevent these injuries. Even for the major leaguers, most of whom were damaged in high school only to have the UCL injuries happen once they’ve hit the pros.